Fuel cells have been used for many years to provide electrical power from chemical reactions. The use of microbes in fuel cells to provide the necessary chemical reactions has also been extensively investigated. Such fuel cells are known as microbial fuel cells (MFCs). At the anode of an MFC, microbes oxidize the electron donors and transfer the electrons to an electrode. At the MFC cathode, electrons are received and oxygen gas is reduced. Unfortunately, energy recovery in MFCs suffers from several significant and undesirable reductions in efficiency. These issues include voltage loss from reduction of O2 at the cathode, diffusion of dissolved O2 into the anode compartment, and methane production in the anode compartment. Accordingly, it would be an advance in the art to provide improved microbial chemical to electrical energy conversion.